class BankAccount:
    def __init__(self , money):
        self.__balance = money
    def withdraw(self, withdrawMoney):
        print(self.__balance)
        if withdrawMoney > self.__balance:
            print(f"余额不足，无法取款")
        else:
            self.__balance -= withdrawMoney
            print(f"取款成功，余额还有{self.__balance}")
Tom = BankAccount(100)
Tom.withdraw(50)